Rules - Read before posting!

Use Google or our daily threads for basic questions and rulings queries, and check out /r/yugioh101 if you're just starting or returning. The former does apply to asking for decklists, so stop asking for them as their own posts.

I didn't see anything about effects that trigger as a result of it being a specific phase of the turn, so I'm going to just write up an explanation for people to reference. By the way, great guide to game mechanics; very helpful explaining things to players of all skill levels :)

Effects By Phase

Effects that trigger by phase (such as Gladiator Beast monsters, Fire King High Avatar Garunix's Special Summon effect, Lightsworn monsters that mill at End phase, etc.) do not follow standard SEGOC rules. Instead, they activate and resolve on separate chains. The order these effects can activate depends on who the turn player is, and how priority to activate effects is conducted between the two. The order of priority goes:

Turn Player's Mandatory Effects

Opponent's Mandatory Effects

Turn Player's Optional Effects

Opponent's Optional Effects

Priority between players can be passed from one to another, but if both the turn player and opponent pass priority to activate a mandatory effect while both have one to resolve, the turn player must resolve a mandatory effect.

Example: Let's say Player A has conducted battle with Gladiator Beast Retiari, Gladiator Beast Bestiari, and Gladiator Beast Laquari during their Battle Phase, and all have survived battle, allowing them to activate their effects at the end of the Battle Phase. Player A is allowed to choose the order in which these effects activate and resolve. So Player A can activate Retiari's effect first to return itself to the Deck and summon a Gladiator Beast monster (if that monster has an effect that triggers when summoned, that effect can activate at that time, before the effects of the other Gladiator Beasts to tag out activate), then after that sequence of events, activate Bestiari's effect to tag out and summon another Gladiator Beast monster, and finally Laquari's effect. The order those effects can activate and resolve is flexible, so it can go Retiari, Bestiari, Laquari; Laquari, Retiari, Bestiari...and so on.

Example 2: Let's say Player A has activated Mind Control to take control of Player B's Wind-Up Zenmaines. During Player A's Main Phase 2, Player B used Effect Veiler to negate the effects of Zenmaines (after Zenmaines applied its Continuous Effect to save itself from destruction by detaching an Xyz Material). Now it is Player A's End Phase. Because Player A at the start of the End Phase controls both Zenmaines as well as the effect of Mind Control (to return control of the monster to the opponent), and because both are mandatory to resolve at the End phase, Player A has priority to activate/resolve one of these. However, Player A can pass priority to Player B to activate/resolve mandatory effects (in this case, Effect Veiler wearing off). If Player B does resolve Effect Veiler in this case, then Player A regains priority to activate/resolve mandatory effects, and can choose to resolve Zenmaines before Mind Control, or Mind Control before Zenmaines. If Player B does not resolve Effect Veiler in this case, then Player A regains priority to activate/resolve mandatory effects, and must at this point choose to resolve either Zenmaines or Mind Control. This is because the effects are mandatory, and game mechanics mandate that if both the turn player and opponent have passed priority to activate/resolve mandatory effects, the turn player must resolve one, so as to not form an infinite loop of priority-passing. This logic also extends to Lightsworn monsters being negated by Effect Veiler at the End Phase.

Example 3: It is Player A's Standby Phase, and Player A activates and resolves the effect of Treeborn Frog. Then, Player A activates Enemy Controller from the Hand, tributing Treeborn Frog to take control of one of Player B's monsters. Since multiple chains can form in the Standby Phase, and since Treeborn Frog has no restriction on how many times it can be used per turn, Treeborn Frog is allowed to reactivate its effect, summoning itself to the Field after Enemy Controller has resolved.

I have a "basic" (as in, should be learned but I don't know the answer to) question about mechanics though. When two optional effects want to activate during the same activation window, which player has priority? I would guess the non-turn player (or the player who didn't activate the Chain Link 1 effect in the chain) has priority, otherwise you can chain anything to your Reborn/Heavy/Dark Hole and watch it not get Warninged/Bribed/Starlight Roaded/negated somehow.

Also, do Counter Traps get "priority" when activated? Like for example, if the non-turn player wants to chain something to his Torrential, can the turn player activate Huge Rev before the non-turn player can chain his/her own card?

Thanks. I actually did the bulk of this over the Christmas holidays and forgot about it! Thanks, Google Drive!

If you activate a card, you then pass priority. So I can play Heavy Storm when I have a Starlight Road because I want to pull out a Stardust. But as soon as I activate it, it's your go. If you chain Call of the Haunted to my Heavy Storm, I don't get to play Starlight Road.

That was a complicated answer to a simple question. Basically, it's activate, then see if your opponent responds. It goes back and forth.

Your second question is a little confusing, but I think it should be answered by the above answer.

A's turn.

A summons a monster.

B plays Torrential. He now has to pass the chance to chain to player A.

A activates Huge Rev

I don't think Counter Traps really change anything. It still has to be a back and forth thing.

Ok, gotcha. This answers everything. The situation came up when I was playing a Chain Burn player who said I had to give him priority when he/she activated something, which really made me think about this for a while. The argument went on for maybe a minute, then in the end I relinquished my priority to him, then he chooses not to activate anything. I was like WTF...

ASAIK, Counter-Traps don't get any special priority, instead you would use them so that you can prevent your opponent responding with anything other than their own counter-trap of which most run only a few including the solemn brigade, etc.

"When" "do" is always going to happen. You have to do it and it won't ever miss timing. It will activate after the current chain resolves.

"If" "you can" has the ability to always happen. You don't have to do it, but if you want to then it will activate after the current chain resolves.

"When" " you can" may happen, if its activation requirements were just triggered.
It can miss timing. It will activate after the current chain.

"If" "you can" are the best, because sometimes mandatory effects can mess you up (Zenmaines), and optional "when" effects can miss timing. So you basically always get to choose whether to use them or not.

Just one small thing to note about the Damage Step: "Destroy a monster" happens as part of damage calculation. This is important to keep in mind in case, for example, your Fossil Dyna is destroyed in battle and you take Battle Damage. You would be allowed to summon Tragoedia since Fossil Dyna is destroyed and its continuous effect no longer applies. If destruction happened later you would not be allowed to summon Tragoedia. Similarly, Stardust Dragon in Defense Position can't negate Red Dragon Archfiend's effect after damage calculation if RDA attacked it even though it's on the field because it was destroyed in the battle.

In short, Substep 7 should be removed. The rest look fine. I would add small explanations of what happens in each step (for example, End of the Damage Step is when a monster destroyed in battle goes to the graveyard).

Konami is sort of trying to scoot away from the word "priority" like that smelly dude on the bus. When they introduced the Fast Effect Timing chart they didn't use the word at all which is odd given that the article is heavily related to the concept of priority and why people think Konami may be trying to move away from "priority". People have some misconceptions about what it means that are very hard to get rid of, so the word will probably be replaced somehow at some point.

Asmodeus may believe that "priority is gone," a common but incorrect claim after the TCG rule change about using Ignition Effects in response to summons.

Personally I don't have any issue with the word, I'm certainly not replacing "the turn player has priority" with "the turn player has the ability to activate a card or effect first" any time soon. Some are taking a cue from Konami to start reducing its usage though.

Priority is no longer an official term. The concept is still there, but since it is no longer an official term, it should not be used. In my judging experience, using "slang" terms ie. nomi, semi-nomi is frowned upon when judging.